🚴 Newton’s first law of motion
Newton’s first law is sometimes referred to as the Law of inertia.
Imagine riding a bike on a flat road. In the beginning, it takes your effort to turn the pedals to drive the bike and accelerate it (start moving faster). After that when you’re moving faster, it’s easier to turn the pedals to keep moving at a certain speed.
Newton’s first law of motion (the law of inertia) explains this as:
If something is at quiescence (standing still), it prefers to remain as it is until something else makes it move. This Law also says that if something is already moving, it prefers to stay in motion until something else makes it stop. This is inertia.
When you are riding a bike fast, what is easier – to keep going straight or to make a sharp turn? You know when you are moving fast (at a high speed) making a sharp turn, without falling, is difficult and required you to reduce your speed. Why is this so?
Inertia is a tendency of an object to resist changes in its velocity.
Another way of speaking inertia resists changes and it makes the bike go straight. So if you want to make a turn you will have to make an effort to reduce the speed and after that turn safely. The inertia makes the objects do what they do, in the direction they do, until something else makes them change that.
But you know that in reality, if you stop pedaling the wheel, it will gradually start to move more slowly and eventually stop. Why?
This is because of other physical forces, such as gravity and friction, that also act on our planet Earth.
There is no gravity or friction in space. If you travel with a spaceship in outer space in a certain direction – for example to Mars, and you run out of fuel. What will happen? Will your ship stop moving completely as the bike stops when you stop pedaling?
The answer is NO. Your spaceship will continue to move in the same direction with the same scab forever. And it will continue to move in this way until something else makes it stop or change its direction – for example, hit by an asteroid or fall into the gravitational field of a planet.
💡 Observations – let’s check how does it work
Newton’s second law – reed more.
Newton’s third law – see what it says.